The present invention relates to a method of driving a pen recorder such for example as an XY plotter, a graphic printer, or an alphanumeric printer.
There have previously been known multicolor pen recorders having a plurality of pens carrying inks of different colors and successively selectable for desired ink colors to effect multicolor printing. Such a multicolor pen recorder is disadvantageous in that it includes a large and heavy carriage for moving the pens. To eliminate this difficulty, there has been developed a selector mechanism including a drum supporting a plurality of pens and rotatable for selecting desired pens.
For initilization of the carriage when starting printing operation, the carriage needs to be positioned first at a stopper position and then at a home position. To establish the stopper position, the prior pen recorder includes a photointerrupter or optoisolator for detecting the carriage and stopping the same. The optoisolator however is costly and must be located highly accurately.